The most obvious neurological symptoms of Friedreich’s ataxia are poorly coordinated movement, gait disturbances, and dizziness, a study published in the journal International Archives of Otorhinolaryngology confirmed — implying that changes in the vestibular system that governs equilibrium and balance also trouble the vast majority of patients.
Vestibular testing is, for this reason, important since otoneurologic symptoms, or those associated with the portions of the nervous system related to the ear, occur early in the disease. This information could help doctors in monitoring patients with Friedreich’s ataxia.
To study vestibular disorders in people with Friedreich’s ataxia, a team of researchers led by Dr. Hélio Afonso Ghizoni Teive of the Department of Internal Medicine at Hospital das Clínicas in Curitiba, Brazil, analyzed 30 patients ages 6 to 72. The patients had their medical history taken, and underwent an ear, nose and throat checks as well as vestibular evaluations, which assesses the balance function of the inner ear.
Results showed that 66.7% of these patients had movement difficulties, 56.7% had gait disturbances, and 50% had dizziness.
Vestibular testing consisted of caloric testing, where the outer ear canal is subjected to cold or warm air to detect asymmetries in the balance system; gaze nystagmus testing, which assesses involuntary eye movement; rotational chair testing; and optokinetic nystagmus testing, or eye movement while tracking a moving field.
Problematic changes were seen in 90% of patients in all tests, with the majority occurring in those with central vestibular dysfunction. More precisely, 73.4% of the patients showed alterations in caloric testing, 50.1% showed abnormalities in gaze nystagmus testing, 36.7% had disturbances in the rotational chair testing, and 33.4% showed disturbances in the optokinetic nystagmus testing.
“The study emphasizes the importance of the vestibular evaluation for the … diagnosis of neurodegenerative diseases since, in most cases, the otoneurologic symptoms present early and such information may aid in the choice of procedures to be performed in clinical and therapeutic monitoring,” Teive and colleagues wrote in their report, titled “Otoneurological Abnormalities in Patients with Friedreich’s Ataxia.”
Friedreich’s ataxia is an autosomal recessive neurodegenerative disease. The most common symptoms include involuntary limb movements, but nystagmus, or involuntary eye movements, and, in some cases, hearing loss are also common.